SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20455ae2cd54aff8559f9336a14902cbd3764a3cf91fd3026ac984049cd36894' 
  AND token = 'Po6hMn1XwEqz6+8SGoju5UCI/ufj64qegTZwvt/37l4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}